Please also remember (forgive me if this has been sd, I did not read the whole post
) that PP is like the digital darkroom. People use to do color selection (granted they physically had to paint in the color) and dodging and burning was acieved my over/under exposing part of the image in purpose. Different film created different looks...
The good photographers of yesteryear rarely gave a client a photo, "straight out of the camera..."(at least my grandfather never did)
So, to answer your question. No, its not cheating - art is art. Now, if you are just taking a snapshot or doing photojournalism - doing the "fancy" stuff is cheating.